Re: [PATCH v9 2/2] PCI: rockchip: Add Rockchip RK356X host controller driver
From: Rob Herring <robh+dt@kernel.org>
Date: 2021-06-23 21:15:19
Also in:
linux-pci, linux-rockchip
== On Wed, May 5, 2021 at 8:35 PM Simon Xue [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Add a driver for the DesignWare-based PCIe controller found on RK356X. The existing pcie-rockchip-host driver is only used for the Rockchip-designed IP found on RK3399. Tested-by: Peter Geis <redacted> Reviewed-by: Kever Yang <redacted> Reported-by: kernel test robot <redacted> Signed-off-by: Simon Xue <redacted> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> --- drivers/pci/controller/dwc/Kconfig | 11 + drivers/pci/controller/dwc/Makefile | 1 + drivers/pci/controller/dwc/pcie-dw-rockchip.c | 277 ++++++++++++++++++ 3 files changed, 289 insertions(+) create mode 100644 drivers/pci/controller/dwc/pcie-dw-rockchip.cdiff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig index 423d35872ce4..60d3dde9ca39 100644 --- a/drivers/pci/controller/dwc/Kconfig +++ b/drivers/pci/controller/dwc/Kconfig@@ -214,6 +214,17 @@ config PCIE_ARTPEC6_EP Enables support for the PCIe controller in the ARTPEC-6 SoC to work in endpoint mode. This uses the DesignWare core. +config PCIE_ROCKCHIP_DW_HOST + bool "Rockchip DesignWare PCIe controller" + select PCIE_DW + select PCIE_DW_HOST + depends on PCI_MSI_IRQ_DOMAIN + depends on ARCH_ROCKCHIP || COMPILE_TEST + depends on OF + help + Enables support for the DesignWare PCIe controller in the + Rockchip SoC except RK3399. + config PCIE_INTEL_GW bool "Intel Gateway PCIe host controller support" depends on OF && (X86 || COMPILE_TEST)diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile index eca805c1a023..689b06a7d334 100644 --- a/drivers/pci/controller/dwc/Makefile +++ b/drivers/pci/controller/dwc/Makefile@@ -14,6 +14,7 @@ obj-$(CONFIG_PCI_LAYERSCAPE_EP) += pci-layerscape-ep.o obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o +obj-$(CONFIG_PCIE_ROCKCHIP_DW_HOST) += pcie-dw-rockchip.o obj-$(CONFIG_PCIE_INTEL_GW) += pcie-intel-gw.o obj-$(CONFIG_PCIE_KIRIN) += pcie-kirin.o obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.odiff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c new file mode 100644 index 000000000000..3f060144eeab --- /dev/null +++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c@@ -0,0 +1,277 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCIe host controller driver for Rockchip SoCs. + * + * Copyright (C) 2021 Rockchip Electronics Co., Ltd. + * http://www.rock-chips.com + * + * Author: Simon Xue <xxm@rock-chips.com> + */ + +#include <linux/clk.h> +#include <linux/gpio/consumer.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/reset.h> + +#include "pcie-designware.h" + +/* + * The upper 16 bits of PCIE_CLIENT_CONFIG are a write + * mask for the lower 16 bits. + */ +#define HIWORD_UPDATE(mask, val) (((mask) << 16) | (val)) +#define HIWORD_UPDATE_BIT(val) HIWORD_UPDATE(val, val) + +#define to_rockchip_pcie(x) dev_get_drvdata((x)->dev) + +#define PCIE_CLIENT_RC_MODE HIWORD_UPDATE_BIT(0x40) +#define PCIE_CLIENT_ENABLE_LTSSM HIWORD_UPDATE_BIT(0xc) +#define PCIE_SMLH_LINKUP BIT(16) +#define PCIE_RDLH_LINKUP BIT(17) +#define PCIE_LINKUP (PCIE_SMLH_LINKUP | PCIE_RDLH_LINKUP) +#define PCIE_L0S_ENTRY 0x11 +#define PCIE_CLIENT_GENERAL_CONTROL 0x0 +#define PCIE_CLIENT_GENERAL_DEBUG 0x104 +#define PCIE_CLIENT_HOT_RESET_CTRL 0x180 +#define PCIE_CLIENT_LTSSM_STATUS 0x300 +#define PCIE_LTSSM_ENABLE_ENHANCE BIT(4) + +struct rockchip_pcie { + struct dw_pcie pci; + void __iomem *apb_base; + struct phy *phy; + struct clk_bulk_data *clks; + unsigned int clk_cnt; + struct reset_control *rst; + struct gpio_desc *rst_gpio; + struct regulator *vpcie3v3; +}; + +static int rockchip_pcie_readl_apb(struct rockchip_pcie *rockchip, + u32 reg) +{ + return readl(rockchip->apb_base + reg);
Use _relaxed variant.
+}
+
+static void rockchip_pcie_writel_apb(struct rockchip_pcie *rockchip,
+ u32 val, u32 reg)
+{
+ writel(val, rockchip->apb_base + reg);Use _relaxed variant.
+}
+
+static void rockchip_pcie_enable_ltssm(struct rockchip_pcie *rockchip)
+{
+ rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_ENABLE_LTSSM,
+ PCIE_CLIENT_GENERAL_CONTROL);
+}
+
+static int rockchip_pcie_link_up(struct dw_pcie *pci)
+{
+ struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
+ u32 val = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_LTSSM_STATUS);
+
+ if ((val & (PCIE_RDLH_LINKUP | PCIE_SMLH_LINKUP)) == PCIE_LINKUP &&((val & PCIE_LINKUP) == PCIE_LINKUP)
+ (val & GENMASK(5, 0)) == PCIE_L0S_ENTRY)
Perhaps a define for GENMASK(5, 0)
+ return 1;
+
+ return 0;
+}
+
+static int rockchip_pcie_start_link(struct dw_pcie *pci)
+{
+ struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
+
+ /* Reset device */
+ gpiod_set_value_cansleep(rockchip->rst_gpio, 0);With gpiod, 0 means inactive which is reset deasserted. Your DT should have an ACTIVE_LOW flag.
+
+ rockchip_pcie_enable_ltssm(rockchip);
+
+ /*
+ * PCIe requires the refclk to be stable for 100µs prior to releasing
+ * PERST. See table 2-4 in section 2.6.2 AC Specifications of the PCI
+ * Express Card Electromechanical Specification, 1.1. However, we don't
+ * know if the refclk is coming from RC's PHY or external OSC. If it's
+ * from RC, so enabling LTSSM is the just right place to release #PERST.
+ * We need more extra time as before, rather than setting just
+ * 100us as we don't know how long should the device need to reset.
+ */
+ msleep(100);
+ gpiod_set_value_cansleep(rockchip->rst_gpio, 1);
+
+ return 0;
+}
+
+static int rockchip_pcie_host_init(struct pcie_port *pp)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+ struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
+ u32 val;
+
+ /* LTSSM enable control mode */
+ val = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_HOT_RESET_CTRL);
+ val |= PCIE_LTSSM_ENABLE_ENHANCE | (PCIE_LTSSM_ENABLE_ENHANCE << 16);Since you have a write mask, why do you need to do a read-mod-write? And why not use HIWORD_UPDATE_BIT?
+ rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL); + + rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_RC_MODE, + PCIE_CLIENT_GENERAL_CONTROL); + + return 0; +}